[collectd] New to collectd - About licence of plugins

[Matthias Runge]

On Tue, Apr 04, 2017 at 10:18:23PM +0200, Arthur Havlicek wrote:
> Hello collectd community
> 
> I intend to build a business around this amazing tool, mostly selling a
> collectd integration + plugins. AFAIK plugins in collectd are compiled with
> the daemon making it a single binary, as such it can be considered
> derivative work under a GPL licence.
Hello,

I'm not a lawyer, so the following is just my opinion or best guess.
I hope it might still help you.

Looking at the copying file[1], your question is more complicated, as
it's licensed under MIT and under GPL.

IMO it would be fine to provide e.g plugins written in python to be
distributed under a different license, like Apache license. There are a few
examples of this already.

> 
> I wanted to know whether a non-free licencing over a collectd plugin was
> considered respectful of collectd licence in itself. I expect this to be the
> original wish of collectd to enable as much contributor as possible and
> allow they licence their work the way they want, but I found no other
> example yet or documentation that this is even possible to release a
> modified collectd package containing non-free plugins which is restricted.

Food for thought: as a customer relying on the functionality, you would
probably be willing to pay for support, like getting help with
installation, get a hand when it breaks, report false values, crashes,
whatever. You could offer the plugin under the same license as collectd
and offer professional support. Ideally, your plugin would be part of
upstream collectd.
> 
> As I'm not a lawyer, I query explicit allowance from collectd authors and
> strongly hope it is possible to distribute a plugin with a non-free plugin
> as this would allow me to deploy efficient applications without complex
> pipelining. Of course, non-free licencing would only limit to the plugin and
> would still make me liable of giving source code of collectd parts which are
> covered by free licence.

Re-licensing free software is kind-of tricky. It requires consent of all
authors; there have been a few occasions where this happened. Ususally
projects try to eliminate this issue by requiring a contributor
agreement before accepting patches.

Matthias

[1] https://github.com/collectd/collectd/blob/master/COPYING#L1-L9
-- 
Matthias Runge <mrunge at matthias-runge.de>